A deadly viral outbreak is currently spreading at an alarming rate throughout countries of the Middle East. So far, little can be done for patients struck down by the deadly MERS pathogen, as no cure or vaccine currently exists. Therefore, it comes as a great relief to find that scientists are currently researching novel methods to combat the disease, which is now rampaging through the Arabian Peninsula. So far, a two-drug cocktail has shown promise in stunting the MERS virus in macaque monkey models.
MERS is an abbreviation for Middle East Respiratory Syndrome, first witnessed in 2012, and is disseminated through the population on a person to person basis.
The exact origins are uncertain, but studies have suggested the bat population could, in part, be responsible for original disease transmission.
In addition, scientists have recently discovered antibodies circulating within the camel population, which may have been directed against either the MERS virus, or a remarkably similar virus. Whether this finding has any direct implications on infectivity and spread amongst the human population remains to be seen. Experts in the field of virology are also not ruling out the possibility that other animals might serve as intermediate hosts or reservoirs for the MERS virus.
The virus that causes the syndrome is taxonomically classified as a coronavirus (MERS-CoV), as specified by the Coronavirus Study Group of the International Committee on Taxonomy of Viruses. MERS often triggers the onset of severe acute respiratory illness, and culminates in the following characteristic signs and symptoms:
- Shortness of breath
- Gastrointestinal issues, including diarrhea
Investigation into new a treatment strategy has been explored at the U.S. National Institute of Allergy and Infectious Diseases (NIAID) Rocky Mountain Laboratories, situated in Montana. A series of macaque monkeys were infected with the MERS virus to assess the efficacy of two anti-viral medications, ribavirin and interferon alpha 2b.
Ribavirin is defined as a nucleoside inhibitor, used to prohibit viral replication, and is commonly used to treat individuals with chronic hepatitis C and human respiratory syncytial virus (RSV); the anti-viral therapy was used during the 2003 Severe Acute Respiratory Syndrome (SARS) eruption, a condition caused by a virus from the same coronavirus family as MERS-CoV. Interferon alpha 2b, on the other hand, is a synthetic variant of a protein molecule released by the human body during times of infection.
The research showed considerable promise. The cocktail of ribavirin and interferon alpha 2b seemed to help alleviate the symptoms of infected monkeys, when compared to those who had not been administered the anti-viral treatments.
Autopsies were also performed on both treated and untreated monkeys to determine the viral count within the tissues. Those subjects who had received medication demonstrated a lower viral load and a lower level of lung tissue damage, when contrasted against the tissues of untreated monkeys.
Against the Clock
Researchers immediately began contemplating potential sources of treatment, when the virus first struck. The natural tendency was to look into drugs that were already on the market, and had been tried and tested for other conditions.
Designing and creating new drugs can be time-consuming and costly, with no guarantee of success. Clinical trials, to determine the safety and efficacy of the medicine, must also be conducted, and a lot of red tape waded through, in order to push out a brand new product.
Setting aside issues with cost, time is also a critical factor. Designing and manufacturing a new drug takes a lot of time. When you are up against the clock, trying to stem the tide of a deadly viral outbreak, you have precious little time.
A Wave of Deaths
The Centers for Disease Control and Prevention (CDC) describe MERS virus’ worrying aptitude for killing its victims. Half of all those that become infected have died, and there is little in the way of medical treatment that can be offered.
Thus far, the disease has failed to spread to the United States. However, a significant number of countries have reported incidents of MERS infection, including France, Germany, Italy and the United Kingdom, with the virus believed to have originally stemmed from the Middle East.
This Saturday, the World Health Organization (WHO) indicated the resultant death tally was now at 54, whilst the total number of infected persons was 114. However, according to The Star, authorities in Saudi Arabia have since alleged there to have been an additional eight people, who have contracted the pathogen, with three of the cases proving fatal.
Limitations to Anti-Viral Cocktail
There are, naturally, some obstacles to the researcher’s investigation. One of the authors of the paper, Dr. Heinz Feldmann, indicates that it is up to medical practitioners as to how they go about attempting to treat their patients. He confesses that some doctors may be disinclined to use the combination of interferon alpha 2b and ribavirin, due to side-effects.
In addition, although ribavirin was administered during the SARS outbreak, clinical trials had not been performed to determine whether it was actually making any difference to patient outcome. When looking specifically at these results, the macaque monkey offers an insight into how the animal model responds to the treatment, but whether this is applicable to humans remains to be seen.
Meanwhile, the CDC is unwilling to take any chances, and seems to be adopting a series of proactive measures to ensure health departments are prepared for any potential outbreak. The organization has helped develop diagnostic assays to detect patient antibodies; presence of specific antibodies, coordinated by a patient’s immune system against MERS-CoV, could indicate a case of infection. Aside from this, MERS-CoV testing equipment is being distributed to health departments across America to guarantee rapid detection.
The CDC is also recommending that individuals who travel to the Middle East, where the spread of the MERS virus is greatest, take the necessary precautions. This includes avoiding close contact with the sick, disinfecting commonly used surfaces and utensils, washing hands for a minimum of 20 seconds with soap and water and disposing of used tissues.
Visitors returning home from Middle Eastern countries, who present with symptoms of MERS, should seek immediate laboratory testing to exclude the virus as a possibility.
Although more research needs to be performed to assess the safety and effectiveness of the two-drug cocktail, the latest study shows considerable promise, particularly in the absence of any viable alternatives. These drugs have been found to stunt the spread of the deadly MERS virus in monkeys; let’s hope they can do the same for human patients.
By: James Fenner